By way of background, standard bolts and nuts have no security feature because they are designed to be fastened and unfastened using standard tools, such as wrenches, which can be easily obtained. For some fastener applications, such as the attachment of valuable assets, security fasteners have been developed to prevent unauthorized fastener removal and theft. One example is security locks for metal alloy vehicle wheels. Metal alloy wheels are typically formed with recess holes in which the security locks are wholly or partially recessed following installation. The recess may be relatively narrow and deep (as commonly found in tuner rims) or somewhat wider and shallower. In some cases the recess sidewall is of varying height such that the recess only partially recesses the security lock. Security locks designed for installation in recess holes include both lock bolts and lock nuts. Such locks are typically formed with a security groove pattern that is only exposed inside the entrance to the recess hole or, if exposed outside the entrance of the recess hole, includes a spin shroud. A special key having a matching security ridge pattern is required to install and remove the locks.
U.S. Patent Publication No. 2011/0116891, entitled “Security Fastener for Wheels with a Recess Hole,” the aggregate disclosures of which is hereby incorporated by reference, is directed to a security fastener designed for installation on a wheel having a recess hole and discloses a number of configurations for both a bolt type and nut type security fastener. U.S. Pat. No. 7,445,414, entitled “High Security Fastener Constructions,” the aggregate disclosures of which is hereby incorporated by reference, is directed to a security fastener featuring a rotatable anti-theft shroud.